GRN and Alzheimer disease: Thus, in mice, increased PGRN expression improved the NCL-like phenotype of PGRN knockout mice (Arrant et al., 2018), inhibited the onset of disease-like phenotypes in TDP-43-related ALS (Beel et al., 2018), as well as pathologies that are not related to TDP-43, such as genetic models of Alzheimer’s disease (Minami et al., 2014; Van Kampen and Kay, 2017), and chemically induced Parkinson’s disease (Van Kampen et al., 2014).